William marshall



(No Model.)

W. MARSHALL.

ELEGTRIG CONDENSER.

Patented Apr. 2, 1889.

JNVENTOR. William flfiUJ/Zdll.

I'VITJVESSES,

A TTOR/VEY.

UNITED STATES PATENT OFFICE.

\VILLIAM MARSHALL, OF NF. YORK, N. Y.

ELECTRIC CON DENSER.

SPECIFICATION forming part of Letters Patent No. 400,866, dated April 2, 1889.

Application filed December 20, 1883- Serial No. 294,214. (No model.)

To all whom it may concern:

Be it known that 1, WILLIAM MARSHALL, a citizen of the United States, residing in the city, county, and State of New York, have invented certain new and useful Improvements in Electric Condensers, of which the following is a specification.

My invention relates to condenser switchboards by which from a given sectional c011- denser or group of condensers any desired capacity may be obtained; and it consistsin a method of connecting condensers to vary the capacity.

An application covering the apparatus herein described was filed by me September 29, 1887, Serial No. 250,99l, and allowed September 10, 1888.

In the accompanying drawings, Figure 1 is a plan of my switch-board. Fig. 2 is a view of a plug therefor, and Fig. 3 is a view of a modified arrangement of. switch-board.

I11 the drawings, A A &c., are a series of plates connected each to a positive leaf or group of leaves of a condenser, H, and B and B &c., are a corresponding series of plates connected each to a negative leaf or group of leaves of the condenser.

D and E are two strips adjacent to the two series of plates, respectively, and each plate is adapted to be connected by a plug, F, with its adjacent strip. The strips are provided at each end with binding-posts Q Q and Q Q for the attachment of line-wires.

Each plate is provided with an independent hole for the reception of the plug when not in use or when a wire connection with some other plate is to be made. Any two corresponding plates of the series, as A and B, are also adapted to be connected by the plug, so as to short-circuit the condenser connected therewith.

The plug F, by which all the connections are made, is provided with a binding-post at its upper end adapted to receive the wire G, by wh ch a connection is made to a corresponding plug, as will be hereinafter described.

In Fig.3 I have shown a modification of the switch-board, wherein the wire G in some instances may be dispensed with, the crossconnections being made directly by the plugs.

hen a number of condensers are connected in multiple arc, their joint capacity is equal to the sum of their separate capacities. 7

Therefore the condensers would have a maximum capacity of one microfarad in multiple arc and a minimum capacity of one one-hundredth microfarad in series.

By means of the switch-board just described I am enabled to readily connect a sectional condenser or a number of condensers, so as to get not only the maximum and minimum capacities, but any intermediate capacity by a combination of the series and multiple-arc connections. I may also use each section of the condenser separately and for separate purposes by plugging into the holes 19 p, &c., and attaching the terminals of the several separate lines to each pair of plugs, respectively. Furthermore, I can take all from posts Q Q with aport-ion of the condensers connected up either in series or multiple series, and can then use the remainder or a portion thereof by connecting directly to their plugs and not using posts Q Q.

To illustrate the manner of combining the series and multiple-arc connections, the plates A, A and A are shown plugged to strip E, and the corresponding plates, B, B and B to the strip D. The three condensers are thus in multiple arc with a joint capacity of three-tenths microfarad, and it will be readily seen that the whole can be similarly connected and their maximum capacity obtainedviz., one microfarad. The plates A A" and B B are in series, A being plugged to E, B connected to A by wire G, and B" plugged to D. Their joint capacity is thus one-twentieth microfarad, and it is apparent that the Whole number can be similarly connected and their minimum capacity obtainedviz., one one hundredth microfarad.

In combining the different methods of 0011- nect-ion to obtain the finer graduations of capacity any group may be connected either in multiple are or in series, and then treated as a single condenser in the calculation. Thus the series group A A" B B, having a capacity of one-twentieth, may be combined in multiple arc with A 13 having a capacity of one-tenth, and their joint capacity will be on e-twentieth plus one tenth, which will equal three-twentieths. The same series group may be combined with the multiple-arc group A A A B B B having a capacity of threetenths, and the joint capacity would then be one twentieth plus three-tenths, equaling seVen-twentieths. In like manner any number of sections in series grouping which tends to minimize the capacity may be added in multiple to one or more of the normal capacity and the finest graduations obtained. Likewise multiple-arc groups of equal or different capacity may be combined in series in an obvious manner. Thus the positive plates A and A are connected by a Wire, G, and the negative plates 13 and B similarly connected. The group thus formed is then placed in series with A and B, which are connected, respectively, to the two strips E and D.

Any well-known form of switch may be used in place of plug F, and any section may be short-circuited, as at A B Having described my invention, I claim The method of varying the capacity of a sectional condenser, which consists in grouping two or more sections in series to reduce the individual capacity of the sections and combining the group thus formed in multiple arc with one or more individual sections.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

WM. MARSHALL.

W itn esses:

WM. A. ROSENBAUM, F. O. GRUEN. 

